1.Research findingsRecently, surgical resection of left ventricular wall (partial left ventriculectomy : PLV) was introduced clinically to treat patients with terminal dilated heart failure. In Japan, heart transplantation is yet inconsistent with reality, and indicative standard criteria for applying PLV to patients with dilated cardiomyopathy (DCM), and causative factors that may influence postoperative prognosis remain to be established. In the present study, cardiac muscle specimens obtained at PLV in DCM patients were immunohistochemically and virologically examined. In some DCM patients, active inflammation and persistent infection with enteroviruses (EV) were shown in the cardiac muscle specimens, suggesting that chronic myocarditis may be a causative and pathological factor associated with DCM. Cycle sequencing of EV genome revealed that the RNA sequences detected were mostly those of coxsackie type B viruses. These findings suggested that pathological detection of active inflammation and persistent EV infection of myocardium in DCM patients may predict postoperative poor prognosis after PLV.2.Prospects for the future researchWe are in a position to assess postoperative prognosis of DCM patients in a long-term basis, since we have accumulated clinical data on increasing number of DCM patients who underwent PLV. We will continue to collect data on immunohistochemical and molecular biological analysis of resected myocardium specimens from DCM patients. By comparatively evaluating these data with respect to prospective prognosis and findings on laboratory tests, we hope to establish a preoperative diagnostic standard for DCM patients as to whether they are properly indicated for PLV.